Did You Know?
The wetlands area of Roxhill Park is one of the most biologically diverse ecology zones within the Seattle City limits?
Learn more about the importance, history, challenges and steps being taken by the Roxhill Bog Committee.
Table of contents:
- Why is Roxhill Bog so important?
- What’s wrong with the bog today?
- What is the community doing to fix this?
- The history of Roxhill Park’s Bog.
- Historical documents related to Roxhill Bog.
1. Why is Roxhill Bog so important?
As the drainage basin for sixty surrounding acres, Roxhill Bog collects sediments and pollutants from rain and storm water run off. Plants absorb some pollutants while the spongy peat soil helps filter sediments. At the headwaters of Longfellow Creek, this wetland acts as an essential water filter for a 3.5-mile long waterway that’s home to coho salmon, ensatina salamanders, and red foxes feeding downstream. The creek drains a 2000-acre watershed and is one of the few year round free-flowing creeks in Seattle.
— Nature in the City Seattle, by Kathryn True and Marie Dolan, Mountaineers Books; May 1, 2003
2. What’s wrong with the bog today?
- The bog’s water levels are too low.
- The bog’s water levels fluctuate too much.
- The reduced water levels could eventually cause the destruction of the natural peat base, which may be irreversible.
- There are several possible contributing factors to the low water levels, including possible flow thru the storm water drainage system and evapotranspiration from the trees, shrubs and forbs planted around the bog.
- We can’t know the exact cause without a study. SPU is currently helping with a preliminary study of the storm drainage system and our committee is looking at the evapotranspiration issue. In addition we need to examine the inflow of water to the bog and look for possible sources of additional water to support rehydration.
- The current condition of the bog and park may be contributing to periodic flooding north along the Delridge corridor, all the way to the North Delridge neighborhood.
3. What is happening to fix this?
We’re currently researching this issue with Seattle City Parks, and are digging into records and the history of the project with them, Seattle Public Utilities, and King County.
Several solutions are possible including some sort of coffer dam between the bog and the storm drains, changes in surrounding vegetation and additional sources of water. Once all information is available and we have a completed history of all events and work done to the Roxhill Bog, we will be able to coordinate a proposal for the following four steps:
- Develop a new park hydrology model.
- Design hardware and/or vegetation changes and possible additional water collection systems.
- The building and installation of it all Follow up study to make sure it’s working.
- It will need to go through Seattle City Parks, Seattle Public Utilities, the King County Department of Natural Resources, and their Waste Water group.
4. The history of Roxhill Park’s bog
Roxhill Bog begins to form 10,000 years ago. Biologist estimates are that Roxhill’s 6 to 10 feet of peat took 10,000 years to accumulate. Source: 3
Westwood and Roxhill, 1953. The park, Westwood Village, and the school areas are all farms and wetlands, still.
For an idea of how old Roxhill Bog is, this Wikipedia article details the state of the world at it’s inception.
1895: USGS maps show two tributaries to Roxhill wetland. Source: 2
1920s: Much of the area was a swampy bog, as far east as 16th Ave SW, even up the hills. Source: 4
1930s: There were productive farms and a dairy on the Roxhill Park land just north of SW Roxbury Street, where today’s baseball fields are. Children played in a large pond north of that in the summer and ice skated on it in the winter. The area was owned by the Kodama family, Japanese farmers forced to relocate to internment camps during World War II. Source: 4
1953: Aerial photos show undeveloped wetland. Source: 1
1959: Aerial photos show 8-10 acre wetland. Source: 2
1960: City receives some of the Roxhill Park land as a donation. Source: 1
W. Roxbury Paving. Peat Bog. 26th Ave. SW. and Barton. Mar 31, 1961.
1965: Westwood Village shopping center is finished by the Skinner Corporation and opens. Source: 4
1966: Skinner Corporation donates it’s land immediately south of Westwood Village across Barton to the Seattle Parks Department. Source: 4
1966: Main storm water line to the north was built. Dates of side lines would require a trip to the City’s document center. Source: E-mail from SPU
1969: City regrades Roxhill Park and covers peat with 1.5-2 feet of topsoil to establish a park lawn. Source: 2
1992: City adopts Longfellow Creek Watershed Action plan which includes goal of restoring historic headwaters in Roxhill Park. Source: 2
Late 1990s: Lutheran Alliance to Create Housing (LATCH) selected by Seattle Housing Authority to be partner in development of Roxbury House and Village. Decision made to restore headwaters of Longfellow Creek. Parks became lead organization. Over $750K raised from individuals, private and public organizations. Source: 1
Aerial of Roxhill Park, 1969.
1999: Neighborhood residents and other stakeholders begin planning with Parks. Starflower and 14 other organizations pledge support. Source: 1
2000: King County Department of Natural Resources completes a hydrology survey. It recommends completion of a full hydrology model and design of subterranean structures to regular water flow. Source: 2
2000: Phase 1 construction and planting. Peat cell 4 exposed. Source: 1
2002: Phase 2 construction and planting. Peat cells 1, 2 and 3 exposed. Source: 1
2007: Starflower and Seattle Urban Nature conduct assessment. Noted that at the end of phase 1, there was standing water through summer in peat cell 4 (southern-most), but at the end of phase 2, no standing water in summer in any peat cell, though cell 4 has water most of the year. Source: 1
2013: The collar on an overflow pipe at the north end of cell 4 has long been too low, causing water that should flow to the northern 3 peat cells to flow into storm drains. During the summer of 2013 the collar height was corrected. Source: Phil Renfrow, Seattle Parks
March 2014: Recent very heavy rains provided enough water to test the cell 4 drain collar height and the flow is corrected. However, cells 1, 2, and 3 remain deficient in water. Source: Phil Renfrow, Seattle Parks
1. Roxhill Park Stewardship Report. Starflower Foundation, 2008
2. Roxhill Park, Hydrologic Investigation and Recommendation. King County Wastewater Treatment Division, DNR. March, 2000
3. Nature in the City Seattle, by Kathryn True and Marie Dolan, Mountaineers Books; May 1, 2003
4. History Link article, White Center — Thumbnail History, HistoryLink.org Essay 8616, By Ron Richardson, July 23, 2008
5. Documents related to Roxhill Bog
Roxhill Park Bog system map
A system map of Roxhill Park’s bog cells, numbered 1-4. The cells are the roughly rectangular areas surrounded by trails on this map, toward the right hand side. The top of the map is north at SW Barton Street. Just off of the top of this map would be the Westwood Village Shopping Center. Just off of the bottom of this map is SW Roxbury Street.
This image from the Roxhill Stewardship report, showing the same area but from the east, may help you to understand which cells are which:
The area where it says “Abandonded Laterals” is cell #1, with cell #2 below that, then cell #3, then cell #4, which is largest, and turns toward the left side of the map.
System map of all the nearby storm and waste water drainage systems near Roxhill Park.
Roxhill Park Hydrologic Investigation and Recommendations Report
A study of the peatland hydrology done by King County Department of Natural Resources. Recommends further study of hydrology, development of water flow model and design of facility to control water. The report’s date is March 2000.
Roxhill Stewardship Report 2007
Starflower Foundation survey and report on the results of the 2000-2007 restoration efforts. Contains background history, description of restoration efforts, and species survey.
Roxhill Bog Committee: Preliminary Findings prepared by David Perasso
The Roxhill Bog Committee’s long term goals are to protect the headwaters of Longfellow Creek in West Seattle and to safely repair the Roxhill Bog to it’s original wetland state, without harm to the park’s neighbors.
If you have or know of any information related to this work in progress, please e-mail any details you know to firstname.lastname@example.org. If you would like to discuss this at one of our meetings or have materials that you would like to share in person, we also meet monthly for our regular Roxhill Park Champions as posted on this website.